Gearing



May 19, 1936. e. A. GILLEN 2,040,933

GEARING Filed Aug. 14, 1954 5 Sheets-Sheet l .30 Ti fill r|||| mm George A. Gz'llen INVENTOR BY 'i' M I AT ORNEY May 19, 1936;

G. A. GILLEN GEARING Filed Aug. 14, 1954 3 Sheets-Sheet 2 llHiilli I mmn "l HEIHEF George A Gillan INVENTOR BY M A ORNEY May 19, 1936. e. A. GI LES GEARlNG Filed- Aug. 14, 1934 3 Sheets-Sheet 3 G'eorgeA Gz'llerz m a T N N R E V m A B Patented May 19, 1936 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to mechanism for efiecting alternate reversals of movement.

Special objects of the invention are to provide apparatus for the purpose, which will be simple, positive and reliable and which will consist of but few, durable parts.

Other objects are to provide special gearing of such character and for the objects mentioned which will be particularly inexpensive and adapted to a wide variety of uses.

The foregoing and other desirable objects are attained by the novel features of construction, combinations, relations and arrangements of parts, all as hereinafter set forth, broadly claimed and illustrated in the accompanying drawings.

In the drawings referred to, several different embodiments of the invention are shown, but as will appear as the invention is understood, the structure may be modified and changed in various ways all within the true intent and broad scope of the claims.

Fig. 1 in the drawings is a broken partial plan view of a form of the invention shown as applied to the operation of an oscillating windshield wiper arm.

Fig. 2 is a broken front view of the mechanism shown in Fig. 1.

Fig. 3 is another broken front view but showing the parts shifted to the position they occupy at the other extreme of movement of the wiper arm.

Figs. 4 and 5 are broken plan and front views respectively of another embodiment, involving a worm and gear in place of the spur gear drive in the first form, an internal instead of an external main drive gear and without the motion multiplying gear set of the first form.

Figs. 6 and '7 are broken and partly diagrammatic views illustrative of modifications in the intermittent drive between the main gear and the coupled reverse motion gears.

The invention consists in principle of a main drive gear designated I0, in the several views, carrying separated groups of teeth as indicated at II, I2, I3, designed to alternately mesh and drive the coacting groups of teeth I4, I5, on the intermeshing gear elements I6, I1.

The intermeshing elements I6 and I! have a 1 to 1 gear ratio and consequently the movement of one will impart an equal, reverse movement to the other. The centers I8, I9, of these elements are soplaced at one side of the main gear II], that at a moment such as indicated in Fig. 2, the first of the one group of teeth II, on the adjoining side of the main gear will engage the first tooth of the group I4, when the teeth of the formerly driving group I3, have passed out of driving engagement with the teeth I5, of the other reverse gear element II. Accordingly, then as gear element I6 is rotated right-handedly under drive-of the main gear ID, the coupled gear element II, will be turned lefthandedly. In such left-handed rotary movement the element I! is turned back to bring the teeth I5 into position for meshing engagement by the next group of teeth or driving pins I2 and this actually takes place the moment following the clearing of pins II from the teeth I4, substantially as indicated in Fig. 3.

In the Fig. 3 position, the driving group I2 on the main gear are engaging and driving the teeth I5 of the lower gear element I1, and consequently rotating that right-handedly. This gear element is in turn rotating the first or upper gear element I6, left-handedly carrying the teeth I4 thereof back into position for driven engagement by the next group of driving teeth I3. Each driven gear therefore when meshed by one set of teeth on the drive gear operates to turn back the other driven gear into position for engagement by the next group of driving teeth, immediately following the departure of the teeth of the first driving group from the gear first driven.

It follows that a member or members connected with the alternately reversing gears may be alternately operated in opposite directions.

The manner of connection with these reversing gears may depend on the uses to which the invention is put. In the case of windshield wiper operation, such as here shown, the wiper arm may be connected direct with one of the gears, or if increased motion or decreased motion is desired, multiplying or reducing gearing may be interposed between the reversing gears and the wiper arm. The latter case is illustrated in Figs. 1, 2 and 3, where there is shown a larger gear 20, carried by the intermittently acting gear I4, meshing with a pinion 2 I, carrying the wiper arm 22. In this particular case, the pinion 2 Us shown as having the same center as the lower intermittent gear I'I, but this it will be evident is not essential, since the pivotal mounting 23, for the wiper arm may be located without respect to the center I9. By properly proportioning the gear train 20, 2|, the angle of movement of the wiper arm may be increased or decreased within practical limits, as required. Without such reduction gearing, it will be apparent that with three groups of driving teeth on the main gear and the parts related as shown, the wiper arm or other element will be given a movement of approximately 120. With motion increasing gearing approximately as illustrated in Figs. 2 and 3, the included angle of movement may be increased to approximately 160. 'Theseifigures however are illustrative and not limiting, asactually'the motion may be increased'to a complete or even several complete revolutions.

Various methods of operating the main drive .gear. may be employed.

In Fig. 1, an electric motor is indicated at 24,

7 having a shaft 25, carrying 'a spur pinion 26, in

mesh with gear 21, carryingpinion 28 in mesh with the main drive gear I9. Also in this View all parts of the gear set except the motor pinion are shown as' mounted on andcarriedby a special bracket 29, bolted or otherwise suitably secured to the motor frame at 30. 7

Figs. 4 and'5 illustrate a variation in drivein volving a worm 3 I, onthe motor shaft operating a worm'gear'32, carrying a pinion 33, in mesh with the internal gear teeth 34, of the main drive .gear and which in this instance, is in the form of an annular internally toothed gear member 35, riding on'the drivejpinion 33 and the three additional idler pinions 36;

V Also in the Fig's. 4-5 form of the invention, the motion increasing gearing is dispensed with and the. wiper armor blade 22 is shown directly fixed .at 3'I,to the shaft 38, of the lower intermittent gear I1. The wiper blade in this case consequently has an active stroke of approximately 120, the angle of movement of the reversing gears. r

' The position of parts in Fig. is different from that of Fig. 2, in that the last driving group I3 ofteeth on the main gear has just left the. lower gear and the first group' I I has not quite reached.

the position of engagement with teeth, of the upper gear. This view illustrates how the leading tooth orpin of one group, such as II, will pass over the other teeth of group I4, invorder-to reach andengage the foremost teeth 'of group I4. I

.Figsfi. and '7 illustrateparticularly a modification. of tooth form "or grouping, wherein the teeth of .each group I I, I2, I3, on the main drive wheel arearranged on an outwardly facing are 39, in-

' stead of concentrically on the wheel, so as to mesh with-a rolling. engagement with the correspondingly arcuately disposed teeth I4, I5 of the intermittent gears.

Fig. 6 illustrates .the setof teeth I I driving upper gear I6. andthe latter turning gear I I, back into position to be meshed by thenext groupof teeth 12, while Fig. '7 illustrates thefirst group I I,

'near the point of leaving gear I6 and gear II,

turned back nearly far-enough for engagement by'the approaching set of teeth I2. The arrangement of the driving teeth on an arc, such as indicated, provides favorable leverage. for starting and stopping the partsin their reverse move- 'ments, it being noted that the pins at the ends of each arcuate group being furthest .from the center of the gear which carries them, will engage the teeth of the driven gear at a point fur- Y ther from the center of the drivengear than the .meet special conditions or requirements. there may be only two groups or there may be intermediate teeth. Other variations in tooth form or grouping may be made to effect difierent desired results and to produce in all cases, a smooth meshing and unmeshing of driver and driven gears.

V The driven gears since they have only a-partial rotary movement may be of true gear .form throughout their inner meshing periphery and have their outer portions contoured to alternately engage and then 'free thev teethon the driver.

The three equi-distantlyspaced groups of teeth 7 provide a desirable movement for windshield.

wipers and the like, but it will be apparent that this number of tooth groups may be varied to more than three groups. By using a greater number of teeth in each driving set increased motion may be imparted to the driven gears. The location of the driven gears at diametrically op- .posite sides of the center'of the driver'provides a most compact arrangement. It is not essential that the two drivengears directly mesh. By way Thus" of example, they may both engage an intermediate sliding rack and thelatter may form the member from which thepower is taken off. 'The un-.

even relation of gearelements as between driving and driven members, such as that illustrated, in which there arethree spaced groups I I, I2, =I3, of

driving elements to two diametrically opposite" spaced groups III, I5, of driven elements, assures V the desired alternate reverse action, becausewhen one set of the elements are in mesh as at the top in Fig. 2, the.elementsl5, at the opposite lower side will be in one of the clear spaces between. the driving" groups and free to be turned back into the, position to be. meshed and driven by thene'xt driving group, such as I2 in Fig.3. The structure .of'the several parts may vary to suit the diflerent purposes .to which the invention is adapted, as contemplated by the intent of the claims.

What isclaimed. is:

.1. Gearing comprising apair'of mutilatedgears lines inwardly concavedtoward'the respective axes of said gearelements and a'common driver for said gear elements operating on a center between the axes -of said gear elements having spaced sets of. gear teeth arranged on, arcuate pitch lines inwardly convexed toward the center of said driver for intermittent meshing engagement with said sets of gear teeth on said gear elements.

GEORGE A. GILLEN. 

